In Africa, the prevalence of diabetes is escalating and remains a concern due to the numerous complications it causes. Vascular damage associated with diabetes leads to a prothrombotic state observed in diabetic indiv...In Africa, the prevalence of diabetes is escalating and remains a concern due to the numerous complications it causes. Vascular damage associated with diabetes leads to a prothrombotic state observed in diabetic individuals. Diabetes is a complex and multifactorial disease involving genetic components. With the aim of preventing complications and contributing to an efficient management of diabetes, we investigated genes likely to lead to a risk of thrombosis, in particular the C677T of MTHFR, G20210A of prothrombin, and R506Q of factor V Leiden in type 2 diabetics in Abidjan receiving ambulatory care. A descriptive cross-sectional study was carried out on consenting type 2 diabetic patients. Mutation detection was carried out using the PCR-RFLP method employing restriction enzymes. Hemostasis tests (fibrinogen, D-dimers, fibrin monomers, and von Willebrand factor) were performed using citrate tubes on the Stage? Star Max automated system. Plasminogen activator inhibitor was assayed by ELISA method, and biochemical parameters were determined using the COBAS C311. The study population consisted of 45 diabetic patients, 51.1% of whom presented vascular complications, mainly neuropathy. Disturbances in hemostasis parameters were observed, with 15.5% of patients showing an increase in fibrin monomers. Mutation analysis revealed an absence of factor V mutation (factor V Leiden) and of G20210A mutation of the prothrombin gene. However, 15.6% of subjects had a heterozygous C677T mutation of MTHFR, with 57% of them being anemic. The exploration of biological and genetic factors associated with thrombotic risk is of significant interest in the optimal management of African type 2 diabetics.展开更多
BACKGROUND A series of long non-coding RNAs(lncRNAs)have been reported to play a crucial role in cancer biology.Some previous studies report that lncRNA CDKN2B-AS1 is involved in some human malignancies.However,its ro...BACKGROUND A series of long non-coding RNAs(lncRNAs)have been reported to play a crucial role in cancer biology.Some previous studies report that lncRNA CDKN2B-AS1 is involved in some human malignancies.However,its role in hepatocellular carcinoma(HCC)has not been fully deciphered.AIM To decipher the role of CDKN2B-AS1 in the progression of HCC.METHODS CDKN2B-AS1 expression in HCC was detected by quantitative real-time polymerase chain reaction.The malignant phenotypes of Li-7 and SNU-182 cells were detected by the CCK-8 method,EdU method,and flow cytometry,respectively.RNA immunoprecipitation was executed to confirm the interaction between CDKN2B-AS1 and E2F transcription factor 1(E2F1).Luciferase reporter assay and chromatin immunoprecipitation were performed to verify the binding of E2F1 to the promoter of G protein subunit alpha Z(GNAZ).E2F1 and GNAZ were detected by western blot in HCC cells.RESULTS In HCC tissues,CDKN2B-AS1 was upregulated.Depletion of CDKN2B-AS1 inhibited the proliferation of HCC cells,and the depletion of CDKN2B-AS1 also induced cell cycle arrest and apoptosis.CDKN2B-AS1 could interact with E2F1.Depletion of CDKN2B-AS1 inhibited the binding of E2F1 to the GNAZ promoter region.Overexpression of E2F1 reversed the biological effects of depletion of CDKN2B-AS1 on the malignant behaviors of HCC cells.CONCLUSION CDKN2B-AS1 recruits E2F1 to facilitate GNAZ transcription to promote HCC progression.展开更多
As a development direction of urban rail transit system,the train autonomous circumambulate system(TACS)can operate in a safer,more efficient,and more economical mode.However,most urban rail transit systems transmit s...As a development direction of urban rail transit system,the train autonomous circumambulate system(TACS)can operate in a safer,more efficient,and more economical mode.However,most urban rail transit systems transmit signals through industrial,scientific,and medical(ISM)frequency bands or narrow frequency bands,which cannot meet the requirements of TACS.As a promising solution,the 5th generation(5G)mobile communication provides more services for the future urban rail transit systems,and covers the shortages of exiting communication technologies in terms of capacity and reliability.In this paper,we first briefly review the research status of current train control system and introduce its limitations.Next,we propose a novel network architecture,and present new technologies and requirements of the proposed architecture for TACS.Some potential challenges are then discussed to give insights for further research of TACS.展开更多
BACKGROUND: Many researches have suggested that apolipoprotein E (APOE) and total cholesterol metabolism are closely related with dementia. In the supposed theory, 219 site of APOE promoter region is near gene coding ...BACKGROUND: Many researches have suggested that apolipoprotein E (APOE) and total cholesterol metabolism are closely related with dementia. In the supposed theory, 219 site of APOE promoter region is near gene coding region, so its polymorphism may result in the abnormality of APOE gene and protein expression, and finally lead to dementia. OBJECTIVE: To observe the association between APOE promoter-219G/T polymorphisms with serum total cholesterol in patients with Alzheimer disease, and compare it with non-dementia people. DESIGN: Case-control, comparative observation. SETTING: Department of Neurology, Fengtian Hospital of Shenyang Medical College. PARTICIPANTS: Fifty-five dementia patients including 27 males and 28 females aged (66±3) years and treated in the Department of Neurology, Fengtian Hospital were selected from January 2002 to December 2005 as the Alzheimer disease group. They all diagnosed according to the DSM-Ⅳdiagnostic criteria of Alzheimer disease instituted by American Psychiatry Association in 1994. Meanwhile, 44 none-dementia patients including 21 males and 23 females aged (66±3) years were selected from other clinical departments of Fengtian Hospital as control group. All the participants were informed the detection and agreed. METHODS: Genomic DNA was extracted from the peripheral blood of all subjects, then 'NEST'PCR, DNA sequence and enzyme digestion were adopted to detect the expression of APOE promoter-219 polymorphism, following by biomedical statistics analysis based on the clinical total cholesterol level. MAIN OUTCOME MEASURES: Polymorphism of APOE promoter-219 G/T and total cholesterol level. RESULTS: All 55 dementia patients and 44 non-dementia ones were involved in the result analysis. ①Allele and genotype frequency: The T allele frequency of the Alzheimer disease group was significantly higher than that in the control group [88.2% (97/110), 54.5% (48/88)], while G allele frequency was remarkably lower than that in the control group [11.8%(13/110), 45.5%(40/88), χ2=8.2, P < 0.01]. The TT allele frequency of the Alzheimer disease group was significantly higher than that in the control group [76% (42/55), 48% (21/44)], while GT+GG allele frequency was remarkably lower than that in the control group [24%(13/55), 52%(23/44), χ2=8.7, P < 0.01]. ②Total cholesterol level: The level of the TT genotype patients in the Alzheimer group was obviously higher than that in GT+GG genotype patients (t =2.46, P < 0.05); the cholesterol level in the two genotypes of the control group was similar (P > 0.05). CONCLUSION: TT genotype and allele T in the APOE promoter-219 polymorphisms are the sensitive gene, and genotype TT has a relationship with the increase of total cholesterol level.展开更多
Objective Cucurbitacins are the highly oxygenated tetracyclic triterpenes,which are predominantly found in the Cucurbitaceae family but are also present in several other families of the plant kingdom.A number of compo...Objective Cucurbitacins are the highly oxygenated tetracyclic triterpenes,which are predominantly found in the Cucurbitaceae family but are also present in several other families of the plant kingdom.A number of compounds of this group have been investigated for their cytotoxic,hepatoprotective,anti-inflammatory,cardiovascular and anti-diabetic activities.In China,the cucurbitacin preparation,which contains mostly cucurbitacin B and cucurbitacin E,has been clinically used for the treatment of the primary liver carcinoma.It has been previously reported that cucurbitacin E could produce cytotoxicity against a variety of cancer cells,and various mechanisms were implicated in its cytotoxic effect.The present study is to investigate the effect of cucurbitacin E on hepatoma cells in vitro and in vivo and to study their potential mechanisms of action.Methods The MTT assay was used to assess the viability of human HepG2 and BEL7402 hepatoma cells in vitro after treatment with different concentrations of cucurbitacin E.The cell cycle distribution was determined by flowcytometric analysis after propidium iodide(PI)staining.The cell cycle-related proteins were detected using western blotting analysis.Implanted mouse hepatoma H22 model was built to evaluate the growth inhibitory effect of cucurbitacin E in vivo in mice.Results Our studies found that cucurbitacin E(10-300 nM)produced anti-proliferative effect on human HepG2 and BEL7402 hepatoma cells in vitro without cytotoxicity.According to flowcytometric analysis,cucurbitacin E arrested the cell cycle at G2/M phase in both HepG2 and BEL7402 hepatoma cells after 24 h treatment.Cucurbitacin E induced the decrease in the level of CDK1 protein and the increase in the level of p21 protein,but had no effect on the levels of cyclin A,cyclin B1 and Cdc25C protein.In in vivo anti-tumor experiment,cucurbitacin E had significant inhibitory effects on the growth of mouse H22 hepatoma cells.Conclusions Cucurbitacin E inhibited the proliferation of hepatoma cells in vitro and in vivo,at least in part,through induction of cell cycle arrest at G2/M phase,which was mediated by concomitant upregulation of p21 and downregulation of CDK1.We consider that cucurbitacin E may be useful in the treatment of liver cancer.展开更多
By means of both a theory for pressure-induced shifts(PS) energy spectra and a theory for shifts of energy spectra due to electron-phonon interaction(EPIP.the pure electronic PS and the PS due to EPI of R1 line,R2 lin...By means of both a theory for pressure-induced shifts(PS) energy spectra and a theory for shifts of energy spectra due to electron-phonon interaction(EPIP.the pure electronic PS and the PS due to EPI of R1 line,R2 line,and U band of GSGG:Cr^3+ at 300 K have been calculated,respectively.The calcualted results are in good agreement with all the experimental data.Their physical origins have also been explained.It is found that the mixingdegree of t2^2(^3T1)e^4T2) and |t2^3 3E>base-wavefunctions in the wavefunctions of R1 level of GSGG:Cr^3+ at 300K is remarkable under normal pressure,and the mixing-degree rapidly decreases with increasing pressure.The change of the mixing-degree with pressure plays a key role not only for the pure electronic'PS of R1 line and R2 line but also the PS of R1 line and R2 line due to EPI.The pressure-dependent behaviors of the pure electronic 'PS of R1 line(or R2 line) and the PS of R1 line(or R2 line) due to EPI are quite different.It is the combined effect of them that gives rise to the total PS of R1 line(or R2 line).In the range of about 15 kar-45kbar,the mergence and /or order-reversal between t2^2(3T1)e^4T2 levels and t2^32T1 levels take place,which cause the fluctuation of the rate of PS for t2^2(3T1)e^4T2(or t2^32T1) with pressure,At 300K,both the temperature-dependent contribution to R1 line(Or R2 line or U band) from EPI and the temperature-independent one are important.展开更多
With the strong-field scheme and trigonal bases, the complete d3 energy matrix in a trigonally distorted cubic-field has been constructed. By diagonalizing this matrix, the normal-pressure energy spectra and wavefunct...With the strong-field scheme and trigonal bases, the complete d3 energy matrix in a trigonally distorted cubic-field has been constructed. By diagonalizing this matrix, the normal-pressure energy spectra and wavefunctions of GSGG:Cr3+ at 70 K and 300 K have been calculated without the electron-phonon interaction (EPI), respectively. Further, the contributions to energy spectra from EPI at two temperatures have also been calculated, where temperatureindependent terms of EPI are found to be dominant. The sum of aforementioned two parts gives rise to the total energy spectrum. The calculated results are in good agreement with all the optical-spectral experimental data and the experimental results of g||(R1) and g⊥(R1). It is found that the contribution from EPI to R1 line of GSGG:Cr3+ with taking into account spin-orbit interaction (Hso) and trigonal field (Vtrig) is much larger than the one with neglecting Hso and Vtrig, and accordingly it is essential for the calculation of the EPI effect to take first into account Hso and Vtrig. The admixture of base-wavefunctions, |t32 2E) and |t22(3T1)e4T2 ), the average energy separation △＝ E[t22 (3T1)e4T2]-E[t32 2E] and their variations with temperature have been calculated and discussed.展开更多
The endoplasmic reticulum-nuclei-1 (ERN1) sensing and signaling enzyme mediates a set of complex intracellular signaling events known as the unfolded protein response. We have studied the effect of hypoxia and ischemi...The endoplasmic reticulum-nuclei-1 (ERN1) sensing and signaling enzyme mediates a set of complex intracellular signaling events known as the unfolded protein response. We have studied the effect of hypoxia and ischemic conditions (glucose or glutamine deprivation) on the expression of several casein kinase-1 and -2 genes in glioma U87 cells and its subline with suppressed function of ERN1. It was shown that blockade of ERN1, the key endoplasmic reticulum stress sensor, leads to an increase in the expression levels of casein kinase-1G2, -1E, -2B and NUCKS1 mRNA, but suppresses casein kinase-1A1, -1D and -2A1. Moreover, the expression levels of casein kinase-1A1, -1D and 1G3 as well as casein kinase-2A1 and -2A2 mRNAs are significantly increased under glutamine dep- rivation conditions both in control and ERN1- deficient glioma cells. At the same time, casein kinase-1E, -2B and NUCKS1 mRNA expression levels are also increased under this condition, but only in cells with suppressed function of ERN1. The expression level of NUCKS1 mRNA, however, is decreased both in control glioma cells and in genetically modified cells, but casein kinase-1G2—only in control U87 cells. Cell exposure to glucose deprivation conditions enhances the expression levels of casein kinase- 1D, 1G3, -1E and -2A1 in both types of glioma cells used, but casein kinase-2B expression levels increase only in cells with suppressed function of ERN1. Hypoxia induces or suppresses the expression of most of the studied genes mainly in ERN1-knockdown cells only. Results of this study show that hypoxia as well as glutamine and glucose deprivation conditions change the expression level most of casein kinase genes and that these effects are dependent on ERN1 signaling enzyme function.展开更多
On the basis of the crystal field theory, the formulae of the EPR g factors of three order perturbation with b 2g ground state for 3d 9/3d 1 ions at rhombic tetrahedral clusters (AX 4) n- have been obtain...On the basis of the crystal field theory, the formulae of the EPR g factors of three order perturbation with b 2g ground state for 3d 9/3d 1 ions at rhombic tetrahedral clusters (AX 4) n- have been obtained. Using these formulae, The authors investigated the EPR g factors of the crystals Cs 2CuCl 4 and T 2CuBr 4. The calculation results agree with the experimental findings.展开更多
A theory for shifts of energy spectra due to electron-phonon interaction (EPI) has been developed. Both thetemperature-independent contributions and the temperature-dependent ones of acoustic branches and optical bran...A theory for shifts of energy spectra due to electron-phonon interaction (EPI) has been developed. Both thetemperature-independent contributions and the temperature-dependent ones of acoustic branches and optical brancheshave been derived. It is found that the temperature-independent contributions are very important, especially at lowtemperature. The total pressure-induced shift (PS) of a level (or spectral line or band) is the algebraic sum of its PSwithout EPI and its PS due to EPI. By means of both the theory for shifts of energy spectra due to EPI and the theoryfor PS of energy spectra, the total PS of R1 line of tunable laser crystal GSGG:Cr3+ at 70 K as well as the ones of itsR1 line, R2 line and U band at 300 K will be successfully calculated and explained in this series of papers.展开更多
文摘In Africa, the prevalence of diabetes is escalating and remains a concern due to the numerous complications it causes. Vascular damage associated with diabetes leads to a prothrombotic state observed in diabetic individuals. Diabetes is a complex and multifactorial disease involving genetic components. With the aim of preventing complications and contributing to an efficient management of diabetes, we investigated genes likely to lead to a risk of thrombosis, in particular the C677T of MTHFR, G20210A of prothrombin, and R506Q of factor V Leiden in type 2 diabetics in Abidjan receiving ambulatory care. A descriptive cross-sectional study was carried out on consenting type 2 diabetic patients. Mutation detection was carried out using the PCR-RFLP method employing restriction enzymes. Hemostasis tests (fibrinogen, D-dimers, fibrin monomers, and von Willebrand factor) were performed using citrate tubes on the Stage? Star Max automated system. Plasminogen activator inhibitor was assayed by ELISA method, and biochemical parameters were determined using the COBAS C311. The study population consisted of 45 diabetic patients, 51.1% of whom presented vascular complications, mainly neuropathy. Disturbances in hemostasis parameters were observed, with 15.5% of patients showing an increase in fibrin monomers. Mutation analysis revealed an absence of factor V mutation (factor V Leiden) and of G20210A mutation of the prothrombin gene. However, 15.6% of subjects had a heterozygous C677T mutation of MTHFR, with 57% of them being anemic. The exploration of biological and genetic factors associated with thrombotic risk is of significant interest in the optimal management of African type 2 diabetics.
文摘BACKGROUND A series of long non-coding RNAs(lncRNAs)have been reported to play a crucial role in cancer biology.Some previous studies report that lncRNA CDKN2B-AS1 is involved in some human malignancies.However,its role in hepatocellular carcinoma(HCC)has not been fully deciphered.AIM To decipher the role of CDKN2B-AS1 in the progression of HCC.METHODS CDKN2B-AS1 expression in HCC was detected by quantitative real-time polymerase chain reaction.The malignant phenotypes of Li-7 and SNU-182 cells were detected by the CCK-8 method,EdU method,and flow cytometry,respectively.RNA immunoprecipitation was executed to confirm the interaction between CDKN2B-AS1 and E2F transcription factor 1(E2F1).Luciferase reporter assay and chromatin immunoprecipitation were performed to verify the binding of E2F1 to the promoter of G protein subunit alpha Z(GNAZ).E2F1 and GNAZ were detected by western blot in HCC cells.RESULTS In HCC tissues,CDKN2B-AS1 was upregulated.Depletion of CDKN2B-AS1 inhibited the proliferation of HCC cells,and the depletion of CDKN2B-AS1 also induced cell cycle arrest and apoptosis.CDKN2B-AS1 could interact with E2F1.Depletion of CDKN2B-AS1 inhibited the binding of E2F1 to the GNAZ promoter region.Overexpression of E2F1 reversed the biological effects of depletion of CDKN2B-AS1 on the malignant behaviors of HCC cells.CONCLUSION CDKN2B-AS1 recruits E2F1 to facilitate GNAZ transcription to promote HCC progression.
基金This work was supported in part by the National Natural Science Foundation of China(U2001213,61971191 and 61661021)in part by the Beijing Natural Science Foundation under Grant L182018 and L201011,in part by National Key Research and Development Project(2020YFB1807204)+1 种基金in part by the open project of Shanghai Institute of Microsystem and Information Technology(20190910)in part by the Key project of Natural Science Foundation of Jiangxi Province(20202ACBL202006).
文摘As a development direction of urban rail transit system,the train autonomous circumambulate system(TACS)can operate in a safer,more efficient,and more economical mode.However,most urban rail transit systems transmit signals through industrial,scientific,and medical(ISM)frequency bands or narrow frequency bands,which cannot meet the requirements of TACS.As a promising solution,the 5th generation(5G)mobile communication provides more services for the future urban rail transit systems,and covers the shortages of exiting communication technologies in terms of capacity and reliability.In this paper,we first briefly review the research status of current train control system and introduce its limitations.Next,we propose a novel network architecture,and present new technologies and requirements of the proposed architecture for TACS.Some potential challenges are then discussed to give insights for further research of TACS.
文摘BACKGROUND: Many researches have suggested that apolipoprotein E (APOE) and total cholesterol metabolism are closely related with dementia. In the supposed theory, 219 site of APOE promoter region is near gene coding region, so its polymorphism may result in the abnormality of APOE gene and protein expression, and finally lead to dementia. OBJECTIVE: To observe the association between APOE promoter-219G/T polymorphisms with serum total cholesterol in patients with Alzheimer disease, and compare it with non-dementia people. DESIGN: Case-control, comparative observation. SETTING: Department of Neurology, Fengtian Hospital of Shenyang Medical College. PARTICIPANTS: Fifty-five dementia patients including 27 males and 28 females aged (66±3) years and treated in the Department of Neurology, Fengtian Hospital were selected from January 2002 to December 2005 as the Alzheimer disease group. They all diagnosed according to the DSM-Ⅳdiagnostic criteria of Alzheimer disease instituted by American Psychiatry Association in 1994. Meanwhile, 44 none-dementia patients including 21 males and 23 females aged (66±3) years were selected from other clinical departments of Fengtian Hospital as control group. All the participants were informed the detection and agreed. METHODS: Genomic DNA was extracted from the peripheral blood of all subjects, then 'NEST'PCR, DNA sequence and enzyme digestion were adopted to detect the expression of APOE promoter-219 polymorphism, following by biomedical statistics analysis based on the clinical total cholesterol level. MAIN OUTCOME MEASURES: Polymorphism of APOE promoter-219 G/T and total cholesterol level. RESULTS: All 55 dementia patients and 44 non-dementia ones were involved in the result analysis. ①Allele and genotype frequency: The T allele frequency of the Alzheimer disease group was significantly higher than that in the control group [88.2% (97/110), 54.5% (48/88)], while G allele frequency was remarkably lower than that in the control group [11.8%(13/110), 45.5%(40/88), χ2=8.2, P < 0.01]. The TT allele frequency of the Alzheimer disease group was significantly higher than that in the control group [76% (42/55), 48% (21/44)], while GT+GG allele frequency was remarkably lower than that in the control group [24%(13/55), 52%(23/44), χ2=8.7, P < 0.01]. ②Total cholesterol level: The level of the TT genotype patients in the Alzheimer group was obviously higher than that in GT+GG genotype patients (t =2.46, P < 0.05); the cholesterol level in the two genotypes of the control group was similar (P > 0.05). CONCLUSION: TT genotype and allele T in the APOE promoter-219 polymorphisms are the sensitive gene, and genotype TT has a relationship with the increase of total cholesterol level.
文摘Objective Cucurbitacins are the highly oxygenated tetracyclic triterpenes,which are predominantly found in the Cucurbitaceae family but are also present in several other families of the plant kingdom.A number of compounds of this group have been investigated for their cytotoxic,hepatoprotective,anti-inflammatory,cardiovascular and anti-diabetic activities.In China,the cucurbitacin preparation,which contains mostly cucurbitacin B and cucurbitacin E,has been clinically used for the treatment of the primary liver carcinoma.It has been previously reported that cucurbitacin E could produce cytotoxicity against a variety of cancer cells,and various mechanisms were implicated in its cytotoxic effect.The present study is to investigate the effect of cucurbitacin E on hepatoma cells in vitro and in vivo and to study their potential mechanisms of action.Methods The MTT assay was used to assess the viability of human HepG2 and BEL7402 hepatoma cells in vitro after treatment with different concentrations of cucurbitacin E.The cell cycle distribution was determined by flowcytometric analysis after propidium iodide(PI)staining.The cell cycle-related proteins were detected using western blotting analysis.Implanted mouse hepatoma H22 model was built to evaluate the growth inhibitory effect of cucurbitacin E in vivo in mice.Results Our studies found that cucurbitacin E(10-300 nM)produced anti-proliferative effect on human HepG2 and BEL7402 hepatoma cells in vitro without cytotoxicity.According to flowcytometric analysis,cucurbitacin E arrested the cell cycle at G2/M phase in both HepG2 and BEL7402 hepatoma cells after 24 h treatment.Cucurbitacin E induced the decrease in the level of CDK1 protein and the increase in the level of p21 protein,but had no effect on the levels of cyclin A,cyclin B1 and Cdc25C protein.In in vivo anti-tumor experiment,cucurbitacin E had significant inhibitory effects on the growth of mouse H22 hepatoma cells.Conclusions Cucurbitacin E inhibited the proliferation of hepatoma cells in vitro and in vivo,at least in part,through induction of cell cycle arrest at G2/M phase,which was mediated by concomitant upregulation of p21 and downregulation of CDK1.We consider that cucurbitacin E may be useful in the treatment of liver cancer.
文摘By means of both a theory for pressure-induced shifts(PS) energy spectra and a theory for shifts of energy spectra due to electron-phonon interaction(EPIP.the pure electronic PS and the PS due to EPI of R1 line,R2 line,and U band of GSGG:Cr^3+ at 300 K have been calculated,respectively.The calcualted results are in good agreement with all the experimental data.Their physical origins have also been explained.It is found that the mixingdegree of t2^2(^3T1)e^4T2) and |t2^3 3E>base-wavefunctions in the wavefunctions of R1 level of GSGG:Cr^3+ at 300K is remarkable under normal pressure,and the mixing-degree rapidly decreases with increasing pressure.The change of the mixing-degree with pressure plays a key role not only for the pure electronic'PS of R1 line and R2 line but also the PS of R1 line and R2 line due to EPI.The pressure-dependent behaviors of the pure electronic 'PS of R1 line(or R2 line) and the PS of R1 line(or R2 line) due to EPI are quite different.It is the combined effect of them that gives rise to the total PS of R1 line(or R2 line).In the range of about 15 kar-45kbar,the mergence and /or order-reversal between t2^2(3T1)e^4T2 levels and t2^32T1 levels take place,which cause the fluctuation of the rate of PS for t2^2(3T1)e^4T2(or t2^32T1) with pressure,At 300K,both the temperature-dependent contribution to R1 line(Or R2 line or U band) from EPI and the temperature-independent one are important.
文摘With the strong-field scheme and trigonal bases, the complete d3 energy matrix in a trigonally distorted cubic-field has been constructed. By diagonalizing this matrix, the normal-pressure energy spectra and wavefunctions of GSGG:Cr3+ at 70 K and 300 K have been calculated without the electron-phonon interaction (EPI), respectively. Further, the contributions to energy spectra from EPI at two temperatures have also been calculated, where temperatureindependent terms of EPI are found to be dominant. The sum of aforementioned two parts gives rise to the total energy spectrum. The calculated results are in good agreement with all the optical-spectral experimental data and the experimental results of g||(R1) and g⊥(R1). It is found that the contribution from EPI to R1 line of GSGG:Cr3+ with taking into account spin-orbit interaction (Hso) and trigonal field (Vtrig) is much larger than the one with neglecting Hso and Vtrig, and accordingly it is essential for the calculation of the EPI effect to take first into account Hso and Vtrig. The admixture of base-wavefunctions, |t32 2E) and |t22(3T1)e4T2 ), the average energy separation △＝ E[t22 (3T1)e4T2]-E[t32 2E] and their variations with temperature have been calculated and discussed.
文摘The endoplasmic reticulum-nuclei-1 (ERN1) sensing and signaling enzyme mediates a set of complex intracellular signaling events known as the unfolded protein response. We have studied the effect of hypoxia and ischemic conditions (glucose or glutamine deprivation) on the expression of several casein kinase-1 and -2 genes in glioma U87 cells and its subline with suppressed function of ERN1. It was shown that blockade of ERN1, the key endoplasmic reticulum stress sensor, leads to an increase in the expression levels of casein kinase-1G2, -1E, -2B and NUCKS1 mRNA, but suppresses casein kinase-1A1, -1D and -2A1. Moreover, the expression levels of casein kinase-1A1, -1D and 1G3 as well as casein kinase-2A1 and -2A2 mRNAs are significantly increased under glutamine dep- rivation conditions both in control and ERN1- deficient glioma cells. At the same time, casein kinase-1E, -2B and NUCKS1 mRNA expression levels are also increased under this condition, but only in cells with suppressed function of ERN1. The expression level of NUCKS1 mRNA, however, is decreased both in control glioma cells and in genetically modified cells, but casein kinase-1G2—only in control U87 cells. Cell exposure to glucose deprivation conditions enhances the expression levels of casein kinase- 1D, 1G3, -1E and -2A1 in both types of glioma cells used, but casein kinase-2B expression levels increase only in cells with suppressed function of ERN1. Hypoxia induces or suppresses the expression of most of the studied genes mainly in ERN1-knockdown cells only. Results of this study show that hypoxia as well as glutamine and glucose deprivation conditions change the expression level most of casein kinase genes and that these effects are dependent on ERN1 signaling enzyme function.
文摘On the basis of the crystal field theory, the formulae of the EPR g factors of three order perturbation with b 2g ground state for 3d 9/3d 1 ions at rhombic tetrahedral clusters (AX 4) n- have been obtained. Using these formulae, The authors investigated the EPR g factors of the crystals Cs 2CuCl 4 and T 2CuBr 4. The calculation results agree with the experimental findings.
文摘A theory for shifts of energy spectra due to electron-phonon interaction (EPI) has been developed. Both thetemperature-independent contributions and the temperature-dependent ones of acoustic branches and optical brancheshave been derived. It is found that the temperature-independent contributions are very important, especially at lowtemperature. The total pressure-induced shift (PS) of a level (or spectral line or band) is the algebraic sum of its PSwithout EPI and its PS due to EPI. By means of both the theory for shifts of energy spectra due to EPI and the theoryfor PS of energy spectra, the total PS of R1 line of tunable laser crystal GSGG:Cr3+ at 70 K as well as the ones of itsR1 line, R2 line and U band at 300 K will be successfully calculated and explained in this series of papers.
